This invention relates to tertiary amine methacrylate-based macromonomers and quaternary salts thereof; particularly macromonomers of dialkyl aminoethyl methacrylates with diallylalkylammonium or allylalkyl phenyl ammoniun or vinyloxypropyl terminal groups, polymers made therefrom and methods of preparation thereof.
Random copolymers of cationic monomers with acrylamide are widely used to improve fines and filters retention during paper manufacture and sludge dewatering in newsprint deinking plants, as well as many other applications in mineral processing, oil recovery, and drinking water treatment.1 Recently, it was demonstrated that graft copolymers, in which cationic units were concentrated on pendant chains, gave an much improved performance over their corresponding random polymers.2,3 However, these graft copolymers were synthesized by a gamma radiation-initiated graft copolymerization. It was very difficult to control the copolymerization and almost impossible to completely analyze the copolymer structure. e.g. the length of grafted side chain and graft density. Copolymerization of acrylamide with cationic macromonomers provides a good approach to prepare such copolymers with required chain length and side chain density by controlling the chain length and charged amount of a macromonomer. Therefore the cationic macromonomer precursors need to be synthesized first.
Tertiary dialkylaminoethyl methacrylate based polymers can easily be converted to cationic polymers by quaternization of the tertiary amine. These cationic polymers are very useful in wastewater treatment and papermaking industries. Therefore, the synthesis of well-defined DMAEMA macromonomers with polymerizable terminal unsaturated group is of both industrial and academic interests.
Macromonomers with polymerizable vinyl terminal group are usually synthesized by end-group functionalization of pre-polymers and chain transfer radical polymerization catalyzed by cobalt compounds. Main problems for these methods are that usually not all of the end groups can be functionalized and the resulting polymers have broad molecular weight distribution.
The initiation method using vinyl-containing initiators is an effective alternative approach to the preparation of well-defined macromonomers with narrow molecular weight distributions. The advantage of this method is that each polymer chain has a terminal vinyl group. The application of the initiation method in the synthesis of poly(meth)acrylate macromonomers is still very limited because it is difficult for an initiator such as alkyllithium to bear an unsaturated group.4 Recently, Nagasaki5 and Lascelles6 synthesized poly(diethylaminoethyl methacrylate) (polyDEAEMA) and poly(dimethylaminoethyl methacrylate) (polyDMAEMA) macromonomers with polymerizable terminal vinyl groups by using less active oxyanionic initiators. However, the molecular weights of the prepared polymers were higher than predicted and the polymer dispersities were about 1.3.
1 Bolto, B. A. Prog. Polym. Sci. 1995, 20, 987
2 Ma, M., Zhu, S. Colloid Polym. Sci. 1999, 277, 123
3 Subramanian, R., Zhu, S., Pelton, R. H. Colloid Polym. Sci. 1999 to appear.
4 Jerome, R., Teyssie, Ph., Vuillemin, B., Zundel, T., Zune, C. J. Polym. Sci. Polym. Chem. 1999, 37, 1
5 Nagasaki, Y., Sato, Y., Kato, M. Macromol. Rapid Commun. 1997, 18, 827
6 Lascelles, S. F., Malet, F., Mayada, R., Billingham, N.C., Armes, S. P. Macromolecules. 1999, 32, 2462
The invention in one aspect provides compounds of the general formula I 
wherein W is a capping group; l is or 1; n is 1-1000; m is 1-5; preferably m is 2;
R1 is selected from CH2xe2x95x90CHxe2x80x94CH2xe2x80x94 and CH2xe2x95x90CHxe2x80x94Oxe2x80x94(CH2)pxe2x80x94; p is 1-5;
R2 is selected from H, CH2xe2x95x90CHxe2x80x94CH2xe2x80x94, and phenyl
and wherein R3-R5 is C1-C4 alkyl, and quaternary salts thereof wherein R6 is C1-C4 alkyl and Xxe2x88x92 is an anion.
Preferably, m is 2 when R3 is CH3.
When amphiphilic macromonomers are needed, R4-R5 are C1-C4 alkyls and R6 is absent to thus represent non-quaternized macropolymers.
When cationic macromonomers are desired, R4-R6 are C1-C4 alkyls, and complementary X are present.
Most preferably, n is selected from 5-200 and, still further preferred, n is 10-100.
Water-soluble cationic macromonomers of dialkylaminoalkyl methacrylate with polymerizable diallylmethylammonium or allylmethylphenylammonium or vinyloxyalkyl terminal groups embodiments of the aforesaid compounds according to the invention were synthesized by N-substituted aminexe2x80x94butyllithium (BuLi) initiated anionic polymerization of dialkylaminoalkyl methaerylate, particularly, DMAEMA and subsequent quaternization. We found that diallylamine-BuLi initiated a living polymerization. The resulting polymers had a very narrow molecular weight distribution with initiator efficiency about 0.25. The initiator efficiency of allylphenylamine-BuLi was as high as 0.63. A capping method was thus developed to improve the initiator efficiency of dilallylamine-sBuLi system. Capped with dimethylacrylamide (DMA) or tert-butyl methacrylate (tBMA), the initiation efficiency of the diallylamine-sBuLi system was increased to a level as high as 0-95. Similarly, DMA-capped vinyloxypropylamine-sBuLi had about 0.6 initiator efficiency, but its uncapped system could not initiate the polymerization. The polymerization produced amphiphilic macromonomers with predictable molecular weight and extremely low polydispersity. The quaternization of the polymers with CH3I and dimethyl sulfate gave corresponding cationic macromonomers with diallylmethylammonium or allylmethylphenylammonium, or vinyloxypropyl end groups, which were readily polymerizable by free radical polymerization mechanism.
Thus, in one aspect of the invention provides the synthesis and characterization of cationic macromonomers with diallylmethylammonium or allylmethylphenyl ammonium or vinyloxypropyl terminal group by a living polymerization of DMAEMA. These vinyl groups are active double bonds for the copolymerization with water-soluble monomers such as acrylamide or other organic soluble monomers such as methymethacrylate (MMA) and styrene (St) to make amphiphillic copolymers 
Thus, the present invention in one aspect provides polyDMAEMA macromonomers with polymerizable terminal vinyl groups synthesized by a living anionic polymerization with N-substituted amine-butyllithium initiator system. We have found that the alkylamine substituent had a strong effect on the initiator efficiency in the order of H less than allyl less than phenyl. We have found that the capping of diallylaminolithium with dimethylacrylamide or t-butylmethacrylate gave high initiator efficiencies and an excellent control of the molecular weight. Still further, we have also found that a one to three-fold LiCl with respect to the initiator gave polyDMAEMA with controlled molecular weight and narrow molecular weight distribution. However, too excess LiCl reduced the initiator efficiency. We have also found that the quaternization of terminal diallylamino and allylphenylamino groups required a strong methylizating agent such as (CH3)2SO4, while the dimethylamino group in the polymer chain was quaternized by CH3I.
We have found that lithium amides prepared from primary amine-BuLi could not initiate the polymerization of DMAEMA. However, when these lithium amides were capped with dimethylacrylamide (DMA), named as capping agent, they could initiated the DMAEMA polymerization and yielded polymers with narrow molecular weight distribution. Thus the invention also provides the synthesis of amphiphilic and cationic macromonomers of DMAEMA with the terminal vinyl or allyl group by the living DMAEMA polymerization initiated by capped primary amine-BuLi systems. Further, we have found that vinyl-terminated poly(DMAEMA) and its corresponding cationic macromonomers or diallylmethylammonium terminated cationic macromonomers are readily copolymerizable with other vinyl monomers such as styrene and acrylamide, while allyl-terminated macromonomers are versatile for further modification, for example, hydrosillation, transformation with epoxy and hydroxyl groups, and synthesis of block and graft copolymers.